Water Pump Rebuild

ZLP955 · Jul 23, 2011

Anyone used a rebuild kit for a small block water pump?
I'd like to keep my original unit, and although it doesn't feel like there's any bearing play, I'm concerned that the main seal could be stuffed from years of no use.
The kit I'm considering looks comprehensive, of quality parts, and contains:
1 - Bearing
1 - Fan hub
1 - Impeller (Stamped Steel)
1 - Cartridge type seal (with mating face)
1 - Inlet pipe
1 - Back plate
6 - Back plate screws with lockwashers
1 - Back plate gasket
2 - Mounting gaskets
Obviously I'll have to press out the old shaft, and the new one in again, but anything else I need to watch out for?

Steptoe · Jul 23, 2011

Yep have rebuilt water pumps a couple times
If u have the press for the bearings etc ok, but it is still a bitch of a job.
Yep my orginal water pump is rebuilt...then stored away....
Just use a off the shelf repro for the last 20 odd yrs now

There is an excellent old post on the subject....would be 5 or 5 yrs old now.
Search function above...dont use the google one its near to hopeless.

What screws up is the bearing, which then screws the seal, then water drops out the vent underneath, and the bearing has play.
The pressed impeller....hit with a a spot weld on the shaft...And DONT clamp the welder earth so the current goes thru the bearing...

Just about everything else is reusable...new backing plate if the sharft has moved back and forth or the impeller sa moved on the shaft....u will know that cause will feel/hear it.

ZLP955 · Jul 23, 2011

Thanks Steps; good idea to spot the impeller onto the shaft!

rogerh · Jul 23, 2011

This is where I got my kit. Be sure to support the pump body when pressing in the shaft. This is a link to rebuild instructions.
When I got my kit I took the pump to a automotive machine shop to have it rebuilt because I didn't have a press. He told me it would take a week to do and after calling a number of times I got it back a month and half later. When I got it home I noticed there was not date code on the pump I got back. When I picked the pump up he didn't charge me and I thought it was because it took so long to get done. Now I realize the reason it took so long is because they likely broke my original pump and they must have replaced it with one from ebay. The pump I got back was the right casting number but no date code. I couldn't complain a lot because I got a pump back at no charge but it wasn't original.

Roger

http://www.corvettemagazine.com/engine/water-pump-rebuild.html

Steptoe · Jul 23, 2011

To rebuild takes a good afternoon.....
And getting that bearing is is a mission, even in a press.
Years ago as a maintance fitter, one of the old guys showed me w trick when dropping new bearings into industrail pumps, on site to save poduction down time.

Either heat the pump casing up evenly with the gas axe...make sure u havnt put any seals in....and hot enough so cant grab hold of it longer than a sec without burning yourself then just drop the bearing in the hole
OR
Use the CO2 fire extinguisher and freeze the bearing....this still requires pressure to drop in..I used a bit of both on the water pump when I saw that with the long bearing, trying to keep straight in the press was going to be a potentual issue.

Bottom line its not a job to be done at home without an acruate jig to line up the bearing in the press.

ZLP955 · Jul 24, 2011

Thanks for the advice guys - and especially the link, Roger - every picture worth 1000 words!

Water Pump Rebuild

ZLP955

Steptoe

ZLP955

rogerh

Steptoe

ZLP955

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